Chapter 4 - An Introduction to Functions - 4-5 Writing a Function Rule - Lesson Check - Page 264: 4

$$V=(d+1)^3$$

Because it is a cube shaped box , so the relationship between volume and edge length should be V= d3 , and in the question since the edge should be 1 in greater that the ball diameter , so the result should be $V=(d+1)^3$